1. Field of the Invention
This invention relates to vehicle safety belt retractors, and more particularly to reel type retractors having ratchet teeth incorporated into the reel, said retractors being of the type which may retract the belt webbing and permit or prevent its extension depending on the posture of a movable pawl bar.
2. Description of the Prior Art
The advantage of retracting means for vehicle safety belts whereby belts are withdrawn when not in use, are well known. Some are of a linear design while others comprise a rotating reel, journaled in the sidewalls of a supporting structure, and biased by means of a coiled spring for winding the belt on the reel. Teeth are generally incorporated on the perimeter of one or two flanges of the reel for locking engagement with a movable pawl bar when the reel is rotated to extend the belt. Various means have been suggested for moving the pawl bar into locking engagement with the reel when the belt is needed for safely restraining the wearer, and moving the pawl bar out of engagement, to permit withdrawing and buckling of the belt, or to permit the wearer to move about with a minimum of restraint, when such restraint is unnecessary.
With such retractors, it occasionally happens that when the pawl bar is moved toward locking engagement, it falls on the tip of the ratchet tooth, or the tips of a pair of ratchet teeth, and therefore slips by to engage the next tooth or pair of teeth. It would be desirable to minimize this additional extension of the belt after the pawl bar has been triggered into locking position, so as to provide more positive restraint and protection. This could be achieved by increasing the number of teeth on the ratchet, but to do so would weaken the teeth and reduce the security of the lock obtained.